Database sizes supported by commercially available database management systems (DBMS) continue to grow as the availability and cost per unit storage of disk-based storage and system memory increases. In general, a database can feature on-disk storage of data, in which data records are stored in one or more tables or other database structures on storage media (e.g. hard disks, optical storage, solid state storage, or the like) and read into main system memory as needed to respond to queries or other database operations. Alternatively, a database can feature in-memory storage of data, in which data records are stored in main system memory. As costs of main system memory continue to decrease, the feasibility of significant use of in-memory features increases. However, data capacity requirements of database systems also continue to increase. As such, hybrid approaches that involve features of both in-memory and on-disk systems are also advantageous.
In some examples of in-memory databases, a columnar table is composed of a delta part and a main part. The delta part receives changes to the table and stores these changes in a persistent log. Upon recovery, the delta part is rebuilt from the log. The columnar table may be stored as a chain of pages in the in-memory database, and each page in the chain can accommodate a different number of rows. Given these varying page capacities, it can be difficult to quickly find a data record having a desired row position value without examining the entire chain of pages.